On measuring the temperature coefficient of resistivity and the thermal expansion coefficient of conductive thin films

We analyze the details of extracting the temperature coefficient of resistivity and the thermal expansion coefficient of thin-film materials from the measured temperature coefficient of resistance of thin-film resistors on supporting substrates. It is shown that this requires two straining experiments, one thermal experiment, and the ability to deposit identical films on two different substrates with known properties. An analysis of experimental data from the literature, which includes the application of accepted rules from the Guide to the Expression of Uncertainty in Measurement (GUM), reveals that the violation of the stated requirements usually leads to inconsistent or arbitrary results.